检索结果-南通市图书馆

Applied mathematics 2011年第7期2卷 801-807页

作者： Yehia A. abdel-Aziz Afaf m. abdel-Hameed Khalil I. Khalil 不详

In this paper, we developed a new approach of an analytical model to calculate the radial and transversal components of the acceleration due to the effects of Earth’s albedo. Its effects on the orbital motion of an artificial satellite are introduced. It is assumed that the satellite’s horizon is illuminated and the sun lies on the equator. The magnitudes of those components are obtained and their effects on orbital evolution have been tested for different satellites elements. The perturbations in orbital elements due to Earth’s albedo have been obtained using Lagrange Planetary equation in Gaussian form, in particular the case of LAGEOs satellite, have been found using this new analytical formalism.

关键词： satellite Dynamics Non-Gravitational Forces Albedo Effect Orbital Perturbations Lagrange Planetary Equations

Geology and mineral Chemistry of Uranium-and Thorium-bearing minerals in Rare-metal(NYF)Pegmatites of Um solimate,south Eastern Desert,Egypt

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica sinica(English Edition) 2021年第5期95卷 1568-1582页

作者： mohamed A.ALI Ahmed E.abdel GAWAD mohamed m.GHONEIm Nuclear materials Authority 530 El-MaadiCairoEgypt

The garnet muscovite granitic pegmatite of Um solimate,in southern Egypt,represents a promising asset for strategic and economic metals,especially Bi-Ni-Ag-Nb-Ta as well as U and *** ore bodies occur as large masses,pockets and/or veins of very coarse-grained pegmatites,which consist mainly of K-feldspar,quartz and albite with subordinate muscovite,garnet,and *** data revealed that e U-and e Th-contents of the pegmatites reach up to 39 ppm and 82 ppm,*** studied pegmatites are enriched in primary U and Th minerals(uraninite,coffinite,thorianite and uranothorite)as well as Hf-rich zircon and monazite,which give rise to anomalous radioactive ***-tantalium-bearing minerals(***,microlite and uranopyrochlore),xenotime,barite,galena,fluorite,and apatite are ubiquitous,and,consequently,the studied pegmatites belong tothe Niobium-Yttrium-Fluorine-type(NYF)*** noble metal mineralization includes argentite(Ag_(2)s),native Ni and Bi as well as bismite and *** addition,beryl and tourmaline are observed in pegmatites near the contact with metasediments and ultramafic *** observed compositional variations of Ta/(Ta+Nb)and mn/(mn+Fe)ratios in columbite(0.08-0.45 and 0.11-0.57,respectively)and Hf contents in zircon(3.54-6.46 wt%)may reflectan extreme degree of magmatic fractionation leading to formation of the pegmatite orebody.

关键词： radioactivity rare-metal mineralization pegmatites U/Th-bearing minerals Um solimate Egypt

major and trace elemental analysis in milk powder by inductively coupled plasma-optical emission spectrometry(ICP-OEs) and instrumental neutron activation analysis(INAA)

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2003年第4期15卷 570-576页

作者： A.sroor N.Walley El-Dine A.El-shershaby A.s.abdel-Haleem NuclearPhysicsLaboratory NuclearPhysicsLaboratoryNuclearPhysicsLaboratoryHotLaboratories FacultyofGirlsAinShamsUniversityCairoEgyptFacultyofGirlsAinShamsUniversityCairoEgyptFacultyofGirlsAinShamsUniversityCairoEgyptAtomicEnergyAuthorityCairoEgypt

major and trace element in seven different kinds of milk powder were studied. The concentration of 24 elements were determined by ICP OEs method, from these elements 9 elements determined by INAA. The determination of trace element contents of foodstuffs, especially milk as daily drink for all peoples age which being a complex food has great importance. The elemental analysis of milk is important both as an indicator of environmental contamination and because milk is a significant pathway for toxic metal intake and a source of essential nutrients for humans. The major elements are Ca, K, mg, Na, P and s. While trace element are B, Ba, Co, Cr, Cu, Fe, Li, mn, mo, Ni, sb, se, sn, sr, V, W and Zn. ICP OEs technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of a series of the milk powders mentioned and comparative results of other direct technique such as instrumental neutron activation analysis. Analysis of both standard reference material A 11 milk powder and NBs Orchard leaves for quality accurance had been completed, and used for a relative method calculate. The importance of the major and trace elements to human health was discussed.

关键词： milk powder ICP OEs INAA

statistical Analysis with Dingo Optimizer Enabled Routing for Wireless sensor Networks

在线全文

学校读者我要写书评

暂无评论

Computers, materials & Continua 2022年第11期73卷 2865-2878页

作者： Abdulaziz s.Alghamdi Randa Alharbi suliman A.Alsuhibany sayed abdel-Khalek Department of mathematics College of Science&ArtsKing Abdulaziz UniversityRabigh21911Saudi Arabia Department statistics College of ScienceUniversity of TabukTabukSaudi Arabia Department of Computer science College of ComputerQassim UniversityBuraydah51452Saudi Arabia Department of mathematics and statistics College of ScienceTaif UniversityTaif21944Saudi Arabia mathematics Department Faculty of ScienceSohag UniversitySohag82524Egypt

security is a vital parameter to conserve energy in wireless sensor networks(WsN).Trust management in the WsN is a crucial process as trust is utilized when collaboration is important for accomplishing trustworthy data *** the available routing techniques do not involve security in the design of routing *** study develops a novel statistical analysis with dingo optimizer enabled reliable routing scheme(sADO-RRs)for *** proposed sADO-RRs technique aims to detect the existence of attacks and optimal routes in *** addition,the presented sADORRs technique derives a new statistics based linear discriminant analysis(LDA)for attack detection,moreover,a trust based dingo optimizer(TBDO)algorithm is applied for optimal route selection in the WsN and accomplishes secure data transmission in ***,the TBDO algorithm involves the derivation of the fitness function involving different input variables of *** demonstrating the enhanced outcomes of the sADO-RRs technique,a wide range of simulations was carried out and the outcomes demonstrated the enhanced outcomes of the sADO-RRs technique.

关键词： statistical analysis reliability routing wireless sensor networks linear discriminant analysis dingo optimizer security

sleep as a window to understand and regulate Alzheimer's disease:emerging roles of thalamic reticular nucleus

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第6期20卷 1711-1712页

作者： Haoqi sun shiqian shen Robert J.Thomas m.Brandon Westover Can Zhang Department of Neurology Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA Center for Translational Pain Research Department of AnesthesiaCritical Care and Pain MedicineMassachusetis General HospitalHarvard Medical SchoolBostonMAUSA Division of Pulmonary Critical Care and Sleep MedicineDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA Genetics and Aging Research Unit McCance Center for Brain HealthMass General Institute for Neurodegenerative DiseaseDepartment of NeurologyMassachusetts General HospitalHarvard Medical SchoolBostonMAUSA

Introduction:Alzheimer 's disease(AD) is a common neurodegenerative disorder and the primary cause of dementia. Considerable evidence supports the “amyloid hypothesis,” stating that the pathogenesis of AD is primarily caused by the deposition of amyloid-β(Aβ), which drives tau phosphorylation, neuroinflammation, and neurodegeneration in the brain. The amyloid hypothesis is strengthened by the significant and moderate benefit of lecanemab, a humanized antibody through an anti-amyloid mechanism,showing slowed clinical decline(van Dyck et al.,2023). The recent positive results of anti-amyloid trials have brought back focus on the amyloid hypothesis through biochemical, genetic, and pharmacological approaches(Zhang, 2023).

关键词： Alzheimer inflammation hypothesis

Novel CYP1B1 mutations and a possible prognostic use for surgical management of congenital glaucoma

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2019年第4期12卷 607-614页

作者： mohamed m.Khafagy Nadia El-Guendy marwa A Tantawy mohamed A.Eldaly Hala m.Elhilali abdel Hady A.abdel Wahab Ophthalmology Department Faculty of Medicine Cairo University Cancer Biology Department National Cancer Institute Cairo University Research Department Children's Cancer Hospital

AIm: To identify CYP1B1 gene mutations and evaluate their possible role as a prognostic factor for success rates in the surgical management of Egyptian congenital glaucoma ***: Totally 42 eyes of 29 primary congenital glaucoma patients were operated on with combined trabeculotomy/trabeculectomy with mitomycin-C and followed up at 1 d, 1 wk, 1, 6 and 12 mo postoperatively. Genomic DNA was extracted from peripheral blood leukocytes. Coding regions of CYP1B1 gene were amplified using 13 pairs of primers, screened for mutations using single-strand conformation polymorphism followed by sequencing of both strands. Efficacy of the operation was graded as either a success [maintaining intraocular pressure(IOP) less than 21 mm Hg with or without antiglaucoma medication], or a failure(IOP more than 21 mm Hg with topical antiglaucoma medications). REsULTs: seven novel mutations out of a total of 15 different mutations were found in the CYP1B1 genes of 14 patients(48.2%). The presence of CYP1B1 gene mutations did not correlate with the failure of the surgery(P=0.156, odds ratio=3.611, 95%CI, 0.56 to 22.89); while the positive consanguinity strongly correlated with failure of the initial procedure(P=0.016, odds ratio=11.25, 95%CI, 1.57 to 80.30). However, the Kaplan-meier survival analysis revealed a significantly lower time of IOP control in the subgroup with mutations in CYP1B1 versus the congenital primary glaucoma group without mutations(log rank test, P=0.015).CONCLUsION: seven new CYP1B1 mutations are identified in Egyptian patients. Patients harboring confirmed mutations suffered from early failure of the initial surgery. CYP1B1 mutations could be considered as a prognostic factor for surgery in primary congenital glaucoma.

关键词： CYP1B1 mutations primary congenital glaucoma intraocular pressure trabeculotomy/trabeculectomy with mitomycin-C.

Characterization and beneficiation of the Egyptian black shale for possible extraction of organic matter

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of mining science and Technology 2014年第2期24卷 177-182页

作者： Abd El-Rahiem F.H. Hassan m.s. selim K.A. abdel-Khalek N.A. Central metallurgical Research and Development Institute

The present paper focuses on obtaining concentrate enriched with organic matter that could be suitable for a retorting process from black shale; this is black shale from the safaga area on the Red sea Coast. X-ray diffraction and optical polarising microscope are used in evaluating black shale minerals. Attrition scrubbing and flotation were conducted for enrichment of organic matter in the black shale sample. mineralogical studies revealed that black shale samples contain bituminous calcareous clay stone, quartz, apatite and pyrite. Rabah mine black shale contains 28% organic matter. The results of the different separation techniques indicate that attrition and flotation techniques successively enriched the organic matter in the black shale. The organic matter could be enriched in the black shale and obtained a concen- trate with 59% assavinz and 85% recovery.

关键词： Black shale Kerogen Organic matter Attrition scrubbing Flotation

The optimum conditions for methanol conversion to dimethyl ether over modified sulfated zirconia catalysts prepared by different methods

在线全文

学校读者我要写书评

暂无评论

燃料化学学报 2021年第1期49卷 63-71页

作者： Doaa s.EL-DEsOUKI Amina H.IBRAHIm samira m.abdelAZIm Noha A.K.ABOUL-GHEIT Dalia R.abdel-HAFIZAR Processes Development Department EPRICairo 11727Egypt Refining Department EPRICairo 11727Egypt

sulfated zirconia(sZ)and two promoted 1% mn/sZ catalysts which have been prepared via sol gel(mn/sZ-s)and impregnation(mn/sZ-I)methods were *** morphology of the catalysts was characterized by XRD,BET,NH3-TPD,ICP,sEm and FT-IR *** conversion of methanol to dimethyl ether and hydrocarbons was carried out in the temperature range of 120−300℃.The mn/sZ-s showed the highest activity due to the high surface area with suitable *** optimum condition of mn/sZ-s catalyst was investigated at 200℃ and LHsV of 0.02 h^−1 in a time range from 30 to 210 *** was found that the total conversion decreased from 80.18% to 53.26% at 210 *** reusability of this catalyst was studied at the optimum condition up till four cycles for 1 *** characterization of the reused catalyst showed a significant change in the structure and surface acidity due to the blockage of the surface acid sited by carbonaceous materials.

关键词： catalysts dehydration DmE sulfate content sulfated zirconia

Histopathological alterations in the liver and intestine of Nile tilapia Oreochromis niloticus exposed to long-term sublethal concentrations of cadmium chloride

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Oceanology and Limnology 2015年第4期33卷 846-852页

作者： YOUNIs Elsayed abdel-WARITH abdel-Wahab AL-AsGAH Nasser EBAID Hossam Department of Zoology College of Science King Saud University Department of Animal Production Faculty of Agriculture Al-Azhar University Department of Zoology College of Science El-Minia University

Fingerlings of Nile tilapia Oreochromis niloticus were exposed to 1.68, 3.36, and 5.04 mg/L cadmium(as CdCl2), which represent 10%, 20%, and 30% of their previously determined 96-h LC5 0. After exposure for 20 days, sections of the liver and intestine of treated fish were examined histologically. Histopathological changes varied from slight to severe structural modification, depending on the exposure concentration. The hepatic tissues of fish exposed to 10% LC 50 showed markedly increased vacuolation of the hepatocytes and coarse granulation of their cytoplasm. Abundant erythrocytic infiltration among the hepatocytes was observed in fish exposed to 20% LC5 0. In the intestinal tissues of fish exposed to all doses, goblet cells proliferated and were greatly increased in size, the longitudinal muscularis mucosa was disturbed and, in the crypts of the sub-mucosal layer, apoptosis increased, indicated by large numbers of degenerated nuclei. Large numbers of inflammatory cells and dilated blood vessels were observed in the intestine of the group treated with 30% LC5 0.

关键词： fish tilapia pollutant cadmium liver intestine

Evaluation of Antioxidants, Total Phenolics and Antimicrobial Activities of Ethyl Acetate Extracts From Fungi Grown on Rice straw

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable materials 2019年第7期7卷 667-682页

作者： Bahaa T.shawky mohammed Nagah mosad A.Ghareeb Gamal m.El-sherbiny saad A.m.moghannem mohamed s.abdel-Aziz microbial Chemistry Department National Research CentreDokki-12622CairoEgypt medicinal Chemistry Department Theodor Bilharz Research InstituteKornaish El-NileWarrak El-HadarImbaba(P.O.30)Giza 12411Egypt Botany and microbiology Department Faculty of ScienceAzhar UniversityNasr CityCairoEgypt

Rice straw(Rs)collected from Egyptian agricultural environment(Al-masied village-Alsharqia Governorate-Egypt)was used as substrate for three fungal isolates namely:4b,1Asp,Pleurotus ostreatus NRRL 3501 and mixed culture of(4b,1Asp).Isolates number 4b and 1Asp were identified using the molecular technique(18s rRNA).Isolate 4b and 1Asp,were identified as Trichoderma saturnisporum mN1-EGY and Aspergillus niger mN2-EGY,*** saturnisporum mN1-EGY extract exhibited the highest antimicrobial activity compared to the other fungal *** phenolic,antimicrobial and antioxidant activities were also determined from the ethyl acetate extract of rice straw inoculated by these *** antioxidant scavenging concentration(sC50)values of the tested samples were 88.84,91.45,94.65 and 100.0μg/ml,respectively for Pleurotus sp.,Aspergiluus niger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.,after 15 days incubation,compared to ascorbic acid as positive control with sC50 value equal to 8.0μg/*** phenolic contents(TPCs)were maximum in Pleurotus *** and found to be the most polyphenolic enriched sample(380.64 mg GAE/g dry extract)compared to extracts of Aspergiluusniger,Aspergiluus niger+Trichoderma sp.,and Trichoderma sp.(261.89,198.52,and 119.80 mg GAE/g dry extract),*** GC-ms analysis has been also performed for the promising extracts.

关键词： Rice straw fungi molecular identification antimicrobial antioxidant total phenolics